Tape loop forming mechanism for use with a tape record/playback mechanism

ABSTRACT

A ratchet mechanism is used to separate rotatable and longitudinally movable tape guiding fingers in a video tape recorder. The fingers withdraw the magnetic tape from a tape cassette, form it into a loop and place it around a rotating drum having magnetic tape heads therein.

[ 51 May 2,1972

[54] TAPE LOOP FORMING MECHANISM References Cited FOR USE WITH A TAPERECORD/PLAYBACK MECHANISM OTHER PUBUCAUONS 1 lnvemorl Automatic TapeThreading, R. Johnson et al., p. 968 Vol. 9,

Jan. 19671BM Tech. Disc.

Yuuichi Kanamaru, Saitama-ken, Japan [73] Assignee: Sony Corporation,Tokyo, Japan [22] Filed: Aug. 6, 1970 Primary Examiner-Bernard KonickAssistant Examiner-Jay P. Lucas Attorney-Lewis H. Eslinger, AlvinSinderbrand and Curtis, Morris & Safford [21] Appl.No.: 61,618

[30] Foreign Application Priority Data ABSTRACT Jan. 24, 1970 I Aratchet mechanism is used to separate rotatable and longitudinallymovable tape guiding fingers in a video tape recorder. The fingerswithdraw the magnetic tape from a tape cassette,

Japan.....................................45/6484 [52] US.Cl............179/100.2 T, 179/1002 R, 179/1002 Z,

226/200 .Gllb 15/60, G1 1b 15/66, B65h 23/26 [58] Field of Search formit into a loop and place it around a rotating drum having [51] Int. Cl.magnetic p heads h i 179/1002 T, 100.2 Z, 100.2 R;

274/4; 226/200 10 Claims, 5 Drawing Figures PATENTEDMAY 2 I972 SHEET 10F3 INVENTOR.

YUU/CHI KAN \MARU PATENTEUMAY 2 I972 SHEET 2 OF 3 INVENTOR.

YUU/CHI KANA MARU FATE'N'TEDMAY 2 m2 SHEET 3 0F 3 FIG. 5

I NVEN TOR.

YUU/CHI KANA/ IARU TAPE LOOP FORMING MECHANISM FOR USE WITH A TAPERECORD/PLAYBACK'MECHANISM In order to prepare a tape recorder forplaying material on a magnetic tape or for recording material upon atape, the tape had to be threaded through a pre-determined path in therecorder which generally extended from a supply'reel, past tape headsand then returned to a take-up reel.

This operation was time consuming and required a degree of manualdexterity on the part of the user. Since it also involved handling thetape with ones fingers, the tape was subject to picking up foreignmatter and the fidelity could be reduced.

Various ways were suggested to automatically thread the tape through thechassis of a tape recorder, however, these methods proved to beexpensive and the devices incorporating these methods were difficult tooperate.

Briefly, the present invention is concerned with providing a pluralityof tape guiding fingers which automatically withdraw the tape from acassette, form the tape into a loop and place it around a drum havingrotating magnetic heads therein. The tape guiding fingers are properlyspaced from each other by a control member in the form of a ratchet andpawl. The tape guiding fingers are eccentrically mounted on a platewhereby rotation of the plate produces longitudinal movement of thefingers and by using a series of upstanding lugs, the restraining forceof the ratchet is overcome when the previous finger has left the ratchetthereby maintaining a spaced relationship between the fingers.

It is therefore a principal object of the invention to provide amechanism for properly maintaining a-spaced relationship between tapeguiding fingers.

It is a further object of the invention to mount a plurality of tapeguiding fingerseccentrically on a plate whereby longitu- -dinal as wellas rotational movement can be imparted to the tape guiding fingers.

It is another object of the invention to provide a ratchet and pawlmechanism to maintain tape guiding fingers in proper spacedrelationship.

It is yet another object of the invention to provide a lug on a tapeguiding finger which provides an abutment member to assist in overcomingthe restraining force of the ratchet and pawl at the properpre-determined time.

It is still a further object of the invention to provide a mechanism formaintaining tape 1 guiding fingers properly spaced which is compact,inexpensive to manufacture, has few moving parts and is simple toassemble.

Further objects and advantages of the present invention will becomeapparent as the following description proceeds, and the featuresofnovelty whichcharacterize the invention will be pointed out withparticularity in the claims annexed to and forming a part of thisspecification.

For a better understanding of the present invention, reference may behad to the accompanying drawings in which:

' FIG. 1 is a top view-showing the tape guiding fingers in rest positionand showing a loading plate and ratchet in phantom lines;

FIG. 2 is a top view showing the position of the fingers after theirinitial movement;

FIG. 3 is a top view showing the position of the fingers after the firstand second fingers have passed the ratchet;

FIG. 4 is a perspective view of the fingers and the ratchet and paw];and

FIG. 5 is a top view showing the basic arrangement of the fingers andtheir relationship to a tape recording head in a video tape recorder.

For the purpose of illustrating the present invention, a specific type'of tape guiding mechanism is disclosed. It should be understood,however, that the aspects of the present invention are applicabletoother various types of tape guiding members and it is'not intended tolimit the-present invention to the specific type of tape guide mechanismdescribed and shown.

*Referring'now to the drawings, specifically FIG. 5, there is shown aportion *of a video taperecorder chassis 10. The chassis has mountedthereon a cassette 11 which is well known in the art. Thecassette'houses a take-up reel 12 and a supply reel 13 which arerotatably mounted and have a magnetic tape 14 wound thereon andextending therebetween. The cassette 11 has an opening 15 thereinthrough which the tape 14 can be drawn and a pair of upright-guide posts16 guide the tape 14 for withdrawal from the opening 15.

A tape guide drum 17 is formed in two parts (not shown) whereby it hasupper and lower sections and a magnetic head ora plurality of heads aresecured to either the upper or lower moiety of the drum 17. The magneticheads can apply or pick up a signal to or from the magnetic tape forrecording or listening purposes. The drum is rotatably mounted on thechassis 10 and can be motor driven or otherwise suitably rotated.

The tape guiding fingers-18 are rotatably attached to a loading plate 19having upstanding flanges 20 thereon so as to form a channel. In FIG. 1there is depicted a plate 21 which is secured to a rotatable shaft 22mounted for rotation upon the loading plate 19. The plate 21 has anupstanding tab 23 affixed thereto and extending at approximately a rightangle to said plate. An upstanding post 24 is also secured to the plate21 preferably extending away from the plate in the same direction as thelug 23. A spring 25 has one end fixed to the post 24 and the other endfixed to a tab 26 on the leg 27 which forms one leg of an L-shapedextension on the tape guiding finger 28. The finger 28 is pivotallysecured by a pin 29 to the plate 21 such that the spring 25 biases thefinger in a counterclockwise direction as viewed in FIG. 1 aboutthe pin29. The

rotation of the arm 28 is stopped by the tab 23 on the plate 21 abuttingagainst the leg 27 on the finger 28. The finger 28 has a depending lug30.thereon which abuts against a depending stop 19a on the loading plate19 which maintains the finger in longitudinal axial alignment with theplate 19.

Two parallel fingers 31 and 32 are rotatably secured to the leg 27 ofthe finger 28 by pins 33 and 34 respectively. Each arm has a pair ofdepending lugs 35, 36 and 37, 38 respectively thereon. An abutment 39 isrigidly secured to the loading plate 19 which limits the rotation of thefingers by functioning as a stop. The abutment 39 in conjunction withthe stop 19a maintain the fingers in perfect axial alignment with theloading plate 19. Each finger 28, 31 and 32 has a depending tape guide28a, 31a and 32a respectively thereon which extends at approximately tothe finger on which it is mounted, however, any suitable angle can bechosen. The latter guides serve to guide the tape 14 around the drum 17.A ratchet 40 is rotatably mounted on a bracket 41 which is secured tothe flange 20 on the loading plate 19. The ratchet includes a toothedwheel 42 as shown in FIG. 4 mounted for rotation on a pin 43. Aresilient spring 44 bears frictionally on the ratchet wheel 42 somewhatin the manner of a pawl, however, the spring 44 permits the wheel toslip when sufficient pressure is applied to a tooth of the wheel. Inthis manner, the spring differs from the positive holding force of apawl. The lugs 35 and 37 are designed to strike the teeth on the ratchetwheel 40in their course of rotational movement and each arm 31, and 32is held by a tooth until it is forced against the frictional bias of thespring 44 to overcome the latter force and thereby rotate the ratchetwheel 40 and free the arm for further rotation. The force to overcomethe bias of the spring is supplied by the motor (not shown) which,through a pulley or gear arrangement, drives the plate 21. When the lug23 on the plate 21 strikes the leg 27, the arm 28 is moved. The leg,during its rotation, strikes the lug 36 on the arm 31 which forces thefinger 31 past the restraint of the ratchet wheel 40. Further movementof the leg 27 causes it to strike the lug 38 on the arm 32 and force itpast the restraint of the ratchet wheel 40.

In actual operation, the tape guides 28a, 31a and 32a are initiallybehind the tape 14 as in position A,B,C, shown in FIG. 5. The plate 21is turned by a motor and pulley or gear mechanism. Since the arm 28 iseccentn'cally mounted on the plate 21, and since the arms 31 and 32 arefixed to the leg 27 on the finger 28, rotation of the plate 21 moves thearms 28,

31 and 32 from the point A, B, C, to the point A B C whereby the tape 14is withdrawn out of the cassette 1 1. When the arms are fully withdrawn,the arm 28 begins to rotate as shown in FIG. 2 and the abutment 23 onthe plate 21 bears against the leg 27 to promote the rotation of the arm28. Since the arms 31 and 32 are rotatably connected to the leg 27, theytoo begin a clockwise rotation as shown in FIG. 2. As shown in FIGS. 2and 4, the lug 35 on the arm 31 abuts against a tooth on the ratchetwheel 40 which serves to preclude further movement of the arm 31 sincethe spring 44 resiliently bears on the ratchet wheel 40. The arm 28continues to move until the leg 27 strikes the lug 36. At this point thearm 31 is forced against the tooth of the ratchet wheel 40 withsufficient force to overcome the frictional bias of the spring 44. Thereis now a space between the arms 28 and 31 since the arm 28 was movingwhile the arm 31 was stopped as shown in FIG. 3. The lug,

37 on the arm 32 abuts against a tooth on the ratchet wheel 40 in thesame manner as the arm 31. The leg 27 meets the lug 38 and forces thearm 32 past the ratchet after the arms 31 and 32 have becomesufficiently spatially separated.

Turning now to FIG. 5, the effect of the rotation of the arms 28, 31 and32 will be explained and shown.

As the arm 28 first begins its clockwise rotation, the tape guide 28apulls the magnetic tape 14 to point A forming the tape loop L When thearms 28, 31, 32 are at the position A,,, B C and are separated from eachother, the loop length L is longer than at any other position of itstravel. As the arms 28, 31, 32 continue their rotation to the position AB C the loop length L, is smaller than at 1. whereby the tape is looserbecause more tape is present for a smaller arm spread. The tape 14therefore drops from the arms by gravity and encircles the tape guidedrum 17.

A series of upright guide posts 45, 46 can be used to maintain the tapeoriented properly and a slanted guide post 47 can be used to keep thetape higher on one side of the drum than the other so the tape can bescanned helically by the magnetic heads in the periphery of the drum.

In view of the detailed description included above, the operation of thetape guiding mechanism of the present invention will readily beunderstood by those skilled in the art. While there has been shown anddescribed a particular embodiment of the present invention, it will beapparent to those skilled in the art that various changes andmodifications may be made without departing from the invention in itsbroader aspects, and it is therefore, contemplated in the appendedclaims to cover all such changes and modifications as fall within thetrue spirit and scope of the invention.

What is claimed is:

1. In a tape guiding mechanism for use with a magnetic taperecord/playback mechanism having a chassis, a magnetic tape wound onsaid chassis, at least one magnetic head provided in a tape guide drumon said chassis, and drive means on said chassis to drive the tape, theimprovement comprising,

a. a plurality of arms having tape guiding means thereon,

b. rotating means secured to said arms for rotating said tape guidingmeans around said drum,

c. means for successively spreading apart said arms in response to therotation of said rotating means, and

d. means for stopping said arms at their spread apart positions tomaintain them spaced from each other.

2. In a tape guiding mechanism for use with a magnetic taperecord/playback mechanism having a chassis, a magnetic tape wound onsaid chassis, at least one magnetic head provided in a tape guide drumon said chassis, and drive means on said chassis to drive the tape, theimprovement comprising,

a. a plurality of arms having tape guiding means thereon,

b. rotating means including a plate secured to said arms for rotatingsaid tape guiding means around said drum,

c. stop means on said chassis for separating said arms to maintain themspaced from each other, and

d. biasing means connected to said plate and one of said arms to biassaid arm toward said plate.

3. In a tape guiding mechanism for use with a magnetic taperecord/playback mechanism having a chassis, a magnetic tape wound onsaid chassis, at least one magnetic head provided in a tape guide drumon said chassis, and drive means on said chassis to drive the tape, theimprovement comprising,

' a. a plurality of arms having tape guiding means thereon,

b. rotating means secured to said arms for rotating said tape guidingmeans around said drum, and

c. stop means on said chassis for separating said arms to maintain themspaced from each other, and wherein one of said arms is rotatablyattached to said rotating means and the other arms are rotatably securedto the arm which is rotatably attached to the rotating means.

4. In a tape guiding mechanism for use with a magnetic taperecord/playback mechanism having a chassis, a magnetic tape wound onsaid chassis, at least one magnetic head provided in a tape guide drumon said chassis, and drive means on said chassis to drive the tape, theimprovement comprising,

a. a plurality of arms having tape guiding means thereon,

b. rotating means secured to said arms for rotating said tape guidingmeans around said drum, and

c. stop means on said chassis for separating said arms to maintain themspaced from each other, and wherein one of said arms is eccentricallysecured to said rotating means whereby said arm can move longitudinaloyand can rotate.

5. In a tape guiding mechanism for use with a magnetic taperecord/playback mechanism having a chassis, a magnetic tape wound onsaid chassis, at least one magnetic head provided in a tape guide drumon said chassis, and drive means on said chassis to drive the tape, theimprovement comprising,

a. a plurality of arms having tape guiding means thereon,

b. rotating means secured to said arms for rotating said tape guidingmeans around said drum, and

c. stop means on said chassis for separating said arms to maintain themspaced from each other, said stop means comprising a ratchet wheelhaving teeth thereon and friction means operatively associated with saidratchet wheel to prevent free rotation of said wheel.

6. In a tape guiding mechanism for use with a magnetic taperecord/playback mechanism having a chassis, a magnetic tape wound onsaid chassis, at least one magnetic head provided in a tape guide drumon said chassis, and drive means on said chassis to drive the tape, theimprovement comprising,

a. a plurality of arms having tape guiding means thereon,

b. rotating means secured to said arms for rotating said tape guidingmeans around said drum, and

0. stop means on said chassis for separating said arms to maintain themspaced from each other, and in which all but one of said arms has meansthereon adapted to be engaged by said stop means.

7.A tape guiding mechanism as defined in claim 6 wherein said meanscomprises upstanding lugs which abut against said stop means when saidarms rotated.

8. A tape guiding mechanism for use with a video tape recordercomprising,

a. a plate rotatably mounted on the chassis of said tape recorder,

b. an arm having an L-shaped portion rotatably secured to said plate byone of the L-shaped legs,

0. at least one other arm rotatably secured to the other of saidL-shaped legs,

d. abutment means on said plate for abutting against said other leg,

e. stop means on said chassis adapted to stop the rotation of said otherarm,

f. abutment means on said other arm adjacent said other L-shaped legwherein said other leg against said abutment means on said other arm andovercomes said stop means.

9. A tape guiding mechanism as defined in claim 8 wherein said armhaving an L"-shaped portion is eccentrically located on said plate.

10. A tape guiding mechanism as defined in claim 8 further comprisingspring means connected to said plate and to one of said arm having theL"-shaped portion to bias said leg towards said plate.

a: in 5

1. In a tape guiding mechanism for use with a magnetic taperecord/playback mechanism having a chassis, a magnetic tape wound onsaid chassis, at least one magnetic head provided in a tape guide drumon said chassis, and drive means on said chassis to drive the tape, theimprovement comprising, a. a plurality of arms having tape guiding meansthereon, b. rotating means secured to said arms for rotating said tapeguiding means around said drum, c. means for successively spreadingapart said arms in response to the rotation of said rotating means, andd. means for stopping said arms at their spread apart positions tomaintain them spaced from each other.
 2. In a tape guiding mechanism foruse with a magnetic tape record/playback mechanism having a chassis, amagnetic tape wound on said chassis, at least one magnetic head providedin a tape guide drum on said chassis, and drive means on said chassis todrive the tape, the improvement comprising, a. a plurality of armshaving tape guiding means thereon, b. rotating means including a platesecured to said arms for rotating said tape guiding means around saiddrum, c. stop means on said chassis for separating said arms to maintainthem spaced from each other, and d. biasing means connected to saidplate and one of said arms to bias said arm toward said plate.
 3. In atape guiding mechanism for use with a magnetic tape record/playbackmechanism having a chassis, a magnetic tape wound on said chassis, atleast one magnetic head provided in a tape guide drum on said chassis,and drive means on said chassis to drive the tape, the improvementcomprising, a. a plurality of arms having tape guiding means thereon, b.rotating means secured to said arms for rotating said tape guiding meansaround said drum, and c. stop means on said chassis for separating saidarms to maintain them spaced from each other, and wherein one of saidarms is rotatably attached to said rotating means and the other arms arerotatably secured to the arm which is rotatably attached to the rotatingmeans.
 4. In a tape guiding mechanism for use with a magnetic taperecord/playback mechanism having a chassis, a magnetic tape wound onsaid chassis, at least one magnetic head provided in a tape guide drumon said chassis, and drive means on said chassis to drive the tape, theimprovement comprising, a. a plurality of arms having tape guiding meansthereon, b. rotating means secured to said arms for rotating said tapeguiding means around said drum, and c. stop means on said chassis forseparating said arms to maintain them spaced from each other, andwherein one of said arms is eccentrically secured to said rotating meanswhereby said arm can move longitudinaloy and can rotate.
 5. In a tapeguiding mechanism for use with a magnetic tape record/playback mechanismhaving a chassis, a magnetic tape wound on said chassis, at least onemagnetic head provided in a tape guide drum on said chassis, and drivemeans on said chassis to drive the tape, the improvement comprising, a.a plurality of arms having tape guiding means thereon, b. rotating meanssecured to said arms for rotating said tape guiding means around saiddrum, and c. stop means on said chassis for separating said arms tomaintain them spaced from each other, said stop means comprising aratchet wheel having teeth thereon and friction means operativelyassociated with said ratchet wheel to prevent free rotation of saidwheel.
 6. In a tape guiding mechanism for use with a magnetic taperecord/playback mechanism having a chassis, a magnetic tape wound onsaid chassis, at least one magnetic head provided in a tape guide drumon said chassis, and drive means on said chassis to dRive the tape, theimprovement comprising, a. a plurality of arms having tape guiding meansthereon, b. rotating means secured to said arms for rotating said tapeguiding means around said drum, and c. stop means on said chassis forseparating said arms to maintain them spaced from each other, and inwhich all but one of said arms has means thereon adapted to be engagedby said stop means.
 7. A tape guiding mechanism as defined in claim 6wherein said means comprises upstanding lugs which abut against saidstop means when said arms rotated.
 8. A tape guiding mechanism for usewith a video tape recorder comprising, a. a plate rotatably mounted onthe chassis of said tape recorder, b. an arm having an ''''L''''-shapedportion rotatably secured to said plate by one of the ''''L''''-shapedlegs, c. at least one other arm rotatably secured to the other of said''''L''''-shaped legs, d. abutment means on said plate for abuttingagainst said other leg, e. stop means on said chassis adapted to stopthe rotation of said other arm, f. abutment means on said other armadjacent said other ''''L''''-shaped leg wherein said other leg againstsaid abutment means on said other arm and overcomes said stop means. 9.A tape guiding mechanism as defined in claim 8 wherein said arm havingan ''''L''''-shaped portion is eccentrically located on said plate. 10.A tape guiding mechanism as defined in claim 8 further comprising springmeans connected to said plate and to one of said arm having the''''L''''-shaped portion to bias said leg towards said plate.